1. Field of the Disclosure
The present disclosure relates generally to image forming devices, and more particularly, to a media dam having a sheet separator having a multi-axis motion for separating media sheets being fed in an image forming device.
2. Description of the Related Art
Typically, an image forming device (such as a printer) includes an apparatus for separating media sheets picked from an input stack and fed into a feed (motion) path of the imaging forming device for an imaging operation (such as printing). Specifically, such an apparatus includes a media sheet separator intended to prevent picking of more than one media sheet at a time.
A variety of means, such as compliant devices including media retarding elements, have been used as sheet separators in image forming devices to accomplish picking of a single media sheet at a time. Further, the compliant devices are used along with a plurality of resistive elements spaced at usually a fixed frequency along a media in a feed path of a media sheet when being picked from an input tray. Such compliant devices are typically of lengths spanning around only a height of a stack of media sheets provided in the input tray. Thus, the compliant devices may be incapable of effectively separating the media sheets being fed into the feed path. One type of resistive elements is in the form of a plurality of dimples on the surface of the media dam, sometimes referred to as a dimpled dam. With dimples, the media sheet being fed encounters a high resistive force resulting in the pick assembly being induced to increase its pick force resulting in a higher force normal to the media stack which in turn increases double feeding of the media, particularly when the media is in a humid environment. Higher pick force also requires greater power from the motor driving the pick assembly with motor stall more likely to occur, especially when feeding heavier media. It would be advantageous to have a media separator that can adjust to the required pick force for a particular media while giving a high resisting force to the second media sheet that has been fed during a double feed condition.
Also, many apparatuses have been designed that include plain or smooth media dams composed of a plurality of metal wear strips provided in the face of the media dam that serve as media sheet separators in input trays carrying the media sheets. Such apparatuses also include a pair of pick rollers that are rotated for feeding the media sheets towards the plain dams. In such apparatuses, a change in feed direction by reversing the pick rollers helps in separating extra media sheets. However, these apparatuses do not effectively prevent multi-feeds of media sheets into a feed path for a printing operation.
It has also been observed that most of the conventional sheet separators on a media dam have the tendency to leave an edge damage mark corresponding to their respective locations on edges of the media sheets. Such marks are undesirable as the marks represent visible defects on printed media sheets. Although, manufacturers of printers/media sheet separators are struggling to eliminate such defects, the problem of separating of the top media sheet from the underlying media sheet without any damage thereto still continues to prevail.
Accordingly, there persists a need for an effective and efficient sheet separator that assists in the separation of a media sheet from underlying media sheets without causing edge damage to the media sheets.